Decline belt conveyors are endless conveyor belts carried on an articulated frame, at least one section of which can be pivoted about a transverse pivot to form an incline or decline (depending on the direction of belt travel) with respect to an adjacent section of the conveyor. While decline conveyors have been used to transport agricultural materials such as feed from a point of storage to feeding stations, prior decline conveyors have a serious problem.
At belt speeds typical in the art, such as about five feet per second, existing decline conveyors have tended to lose material from the portion of the belt passing over the elbow of the decline, particularly if the decline angle is substantial. When traversing the elbow of the conveyor, the material is thrown off the belt (or thrown upwardly and caught by the wind) if it fails to change direction at the elbow as suddenly as the belt does. This problem is not noted in chain conveyors, as shown in U.S. Pat. No. 3,828,916, issued to Patz on Aug. 13, 1974. In the chain drive devices of the latter patent a pintle chain slides agricultural material along a stationary bed embraced by substantial vertical sidewalls. If material is projected from the bed by the chain, which is unlikely, the sidewalls will confine the material until the same or another flight of the chain picks it up again. A chain, being jointed, can also be more flexible than a belt designed for comparable service. The commercial version of the Patz structure can only accommodate a 23 degree decline.
As a result of the difficulty in keeping feed on a single belt traversing a prior decline, such devices require severely restricted decline angles, reduced belt speeds, or high sidewalls. The alternative has been to provide two conveyors disposed at different angles, with one feeding the other, thus requiring two belts, two drives, and other expensive complications. The object realized by the present invention is to largely remove these disadvantages of prior decline belt conveyors.